Desert Pl. Life 15: 123. 1943 ,.
Caudices to 2 dm × 1–2.5 cm, clumps to 3 dm diam. Leaves without resinous odor; rosette 20–40-leaved, 7–25 cm diam.; blade green, appearing whitish, linear, terete or subterete, base flattened, 6–15(–23) × 0.6–1.2 cm, 5–8 mm thick, 1–1.5 times wider than thick, base 10–20 mm wide, surfaces farinose, not viscid, not oily. Inflorescences: cyme 3–5-branched, rounded, (1.5–3 × 0.4–1 dm); branches usually 1–2 times bifurcate; cincinni 2–8-flowered, scarcely circinate, 2–4 cm; floral shoots 1–3 dm × 2–4 mm; leaves 5–15, erect, lanceolate, 1–4 × 0.5–1.2 cm. Pedicels 2–5 mm. Flowers: petals spreading from middle, connate 0.5–2 mm, white or pinkish, narrowly ovate, 5–10 × 2–3 mm, apex acute, corolla 12–20 mm diam.; pistils erect, 6–9 mm; styles 2–3.5 mm. Follicles widely spreading, with adaxial margins 10–45º above horizontal. 2n = 34.
Phenology: Flowering spring.
Habitat: Cliffs and steep rocky slopes
Elevation: 100-600 m
Of conservation concern.
Dudleya densiflora is a distinct endemic that is very local and now rare at the south base of the San Gabriel Mountains near the mouth of San Gabriel Canyon; it is considered seriously threatened (California Native Plant Society, http://cnps.web.aplus.net/cgi-bin/inv/inventory.cgi).
Dudleya densiflora is in the Center for Plant Conservation’s National Collection of Endangered Plants.